1. Field of the Invention
This invention relates to measuring of weight, more particularly to a weighing scale.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional weighing scale for measuring the weight of an object or a person includes a hollow casing having a lower base (A) with a front (A') and a rear section (A"), and an upper outer covering (I) having decorative patterns formed thereon which is made of a plastic material by injection-molding and used for supporting the object or the person thereon. A pressure gauge (C) includes an indicator (C'), a pressure sensor (D) connected to the indicator (C') sensing a pressure produced by the weight and hydraulically actuating the indicator (C') in response to the sensed pressure, and an oil pump (E) having an oil passage connected to the pressure sensor (D) for resetting the indicator (C') to an initial zero position.
Two spaced front fulcrum members (B) with V-shaped notches (B1) are fixed to the front section (A') of the base (A). Two spaced rear fulcrum members (B) with V-Shaped notches (B1) are fixed to the rear section (A") of the base (A).
A lever mechanism (G) has a lever means (G'). The lever means (G') includes a pair of spaced elongated plate members (G2) extending forwards and inwards from the rear section (A") toward the front section (A') and having first front and first rear end portions, a connecting elongated plate member (G3) mounted between the two spaced elongated plate members (G2) adjacent the first rear end portions thereof, and a force exerting plate (G1) fixed to the two spaced elongated plate members (G2) adjacent the first front end portions thereof and resting on the pressure sensor (D). The first rear end portions of the two spaced elongated plate members (G2) have V-shaped notches (G4l) engaging the V-shaped notches (B1) of the rear fulcrum members (B).
The lever mechanism (G) further has a pair of spaced plate-shaped levers (G6) extending rearward and inwards from the front section (A') toward the rear section (A"). The pair of the levers (G6) have second front and second rear end portions respectively having V-shaped notches (G7) formed thereon. The levers (G6) are movably mounted to the front fulcrum members (B) by the V-shaped notches (G7) of the second front end portions engaging the V-shaped notches (B1) of the front fulcrum members (B). The levers (G6) are movably mounted to the lever means (G') by the V-shaped notches (G7) of the second rear end portions engaging two loop retainers (G5) of the lever means (G').
A transmitting means includes an inner covering (H) which is provided between the outer covering (I) and the lever mechanism (G) for transmitting the weight from the outer covering (I) to the force exerting plate (G1) to press the pressure sensor (D). The inner covering (H) includes four retaining members (H2) having four members (H4) with V-shaped notches (H3). The inner covering (H) is movably mounted to the lever mechanism (G) by the V-shaped notches (H3) engaging V-shaped notches (G4) of the levers (G6) and the elongated plate members (G2). A pair of springs (H6) are connected to the inner covering (H) and the base (A). The outer covering (I) is movably covered on the inner covering (H).
When an object is placed, or a person stands onto, the outer covering (I), the weight of the object or the person will be transmitted to cause the force exerting plate (G1) to press against the pressure sensor (D) to hydraulically actuate the indicator (C'), so the weight is converted into the movement of the indicator (C') and displays the weight measure of the object or person.
The above construction is complicated. Since all elements of the base (A), the fulcrum members (B), the lever mechanism (G), and the outer covering (H) are fabricated by die-cutting metal sheets, a lot of dies are needed for the manufacturing and the welding between the elements is also required. The increased cost of the dies and the labor for welding is not economical. Furthermore, it is wasteful that much unused metal material must be disposed of after diecutting.